Gyroscopes are devices which use inertia of a rotary body that is rotating at high speed based on the law of conservation of angular momentum and have been used for a long time in a variety of fields. When a mass is rotating at high speed, even if force to change the orientation of a rotary body is applied thereto, the orientation of the axis of the rotary body is maintained in the original state rather than being changed, because, according to the law of conservation of angular momentum, force of resistance to variation in the orientation of the axis of the rotary body becomes much larger than when the body is not rotating.
Conventional gyroscopes are classified into a gyroscope which uses vacuum as rotational drive force, and a gyroscope which uses an electric motor as a drive source.
In a gyroscope using vacuum, a rotary body is provided with blades so that a mass of the gyroscope is rotated by the flow of air. Due to an advantage of a simple structure, the gyroscope using vacuum is mainly used in a small measuring instrument. This gyroscope is configured in the same manner as the other kind of gyroscope, that is, in such a way that it is supported by a gimbal which is an external support. However, in the case of the gyroscope using vacuum, in consideration of rotation of the gyroscope relative to the external gimbal, it is difficult to arrange a vacuum hose line which extends to the outside. Further, an external vacuum pump is essentially required.
In a gyroscope using an electric motor, a disk-shaped rotary body has a rotating shaft. The rotating shaft may be directly connected to the electric motor or be connected thereto through a speed-up gear unit to increase the rotational speed. In the same manner as the other kind of gyroscope, a rotating shaft of a rotating mass is supported by an external gimbal which is provided so as to be rotatable.
However, this structure requires a motor for rotating a gyroscope, and wheels are perpendicular to each other. Therefore, the volume and weight of the gyroscope are increased. Moreover, much noise is generated, and a loss of energy is very large due to air friction. Also, it is complex to arrange an external electric power supply wire.
In the past, it was common for gyroscopes using rotational inertia to be used in measuring instruments. Nowadays, the use of conventional gyroscopes using rotational inertia is becoming less common, because measuring instruments such as heading indicators, which are more precise and inexpensive and use laser or micro-electro circuits, have been developed and used.
Furthermore, for many years, attempts have been made to develop techniques to install gyroscopes in ships and use them for the purpose of reducing wobbling of the ships. However, recently, gyroscopes are seldom used even in ships. There has been no attempt to use a gyroscope in an aircraft or an automobile.
The reason why gyroscopes cannot be used in transportation means other than ships is due to the fact that physical inertia force of the gyroscopes must be further increased to achieve their intended purpose. That is, to increase inertia force of a gyroscope, a rotating mass must be formed to be heavier, or the speed at which the rotating mass rotates must be increased. As a result, there are various problems including an increase in weight, an increase in space required to install the gyroscope, generation of noise resulting from high-speed rotation, difficulty in continuous supply of energy, a loss of energy, etc.